Molecular Evolution of Hepatitis C Virus: From Epidemiology to Antiviral Therapy (Current Research in Latin America)

The hepatitis C virus (HCV) belongs to the family Flaviviridae and is classified as a member of the Hepacivirus genus. It is a blood-borne pathogen, with a single-stranded, positive-sense RNA genome, and as such, consequent to its error-prone RNA polymerase, it circulates in vivo as a complex population commonly referred to as a quasi-species. Although there is no prophylactic vaccine to date, several treatment regimens are available worldwide thanks to the development of several direct antiviral agents that target specific viral proteins. Studies in Latin America have mainly focused on HCV genetic variability, evolutionary history, and viral as well as host genetic factors associated to response to therapy. The development of antiviral drug and vaccine candidates has also been addressed. This chapter summarizes the results from current research carried out in Latin America on HCV molecular epidemiology (genotype distribution, infection prevalence, modes of evolution) and viral and host genetic diversity (quasi-species diversity, resistance-associated variants, polymorphisms near the IL28B gene). The relevance of these studies for antiviral therapy in our region is discussed.